dana60/9inch

[cozadlance2]

The icewolf. You speak the truth. I bought a work truck. I find all these hotrod f100s fascinating though. Perhaps I need to buy a second truck. a swb 1968 to make a toy out of. You are correct- she will work all day without a wimper now that the worst of the bugs are out of her system. Yes. The f250 needs a stablemate. A playful one. First I need a garage. Patience...

[Racer Z]

The 390 is a 360 with a bigger crank. This means there is more torque, at a slightly lower RPM and a slightly lower redline.

I have a fresh 390 in my F250. I have had it up to 90. I didn't run it that way for long, the engine sounded like it was ready to explode. I do however, cruise at 70 for as long as I need to. The engine sounds fine. On occasion I can accelerate to pass a slower car. (Put down the phone and drive.) That's one thing nice about a big motor is being able to accelerate. My Honda Accord is done at 60. I can accelerate to save my life. But, as I romp on the throttle of my truck, I can also watch the gas gauge drop. It's a trade off.

cozadlance2, I've read some of your other threads. That noise that you complained about in more than one thread is your belt driven fan. I went electric and now it sounds like and gas engine, not a jet turbine. I've got a fresh 390, electric fan, manual steering, C6 auto and a lumber rack. I get 10 MPG. I get 10 MPG going up hill into the wind with a full load and I get 10 MPG down hill, down wind, empty. It's a parachute on wheels.

[cozadlance2]

Good Info. Thank you. The sound is scarier when it is not identified. Earlier today I was reminded that I have an f250 not a Volkswagen. Some here warn against electric fans. I am yet undecided. I need to ponder a while longer if it is a real need or just a wanting to fiddle. Perhaps I need a project truck.

[Racer Z]

People fear things they don't understand.

Once you're doing 30 mph there is enough airflow through the radiator that you don't need a fan at all.

[GSequoia]

Some here warn against electric fans. I am yet undecided.

As long as the fan pulls an equal amount of air (CFM) as the mechanical fan (I don't know that value, nor how to calculate it) you'll be fine. I may consider going electric one day after I upgrade the alternator. When you're on the highway at speed the mechanical fan is doing nothing but wasting energy, the air flowing through the radiator from your movement is more than it's pulling.

Okay, maybe in the perfect wind conditions it's doing something...

[robwymer]

[quote="averagef250"]A 2.5X gear is something you'd only consider if you were trying to set a land speed record. You'd be gearing your truck completely out of it's useful torque range under say 80 MPH.

3.54's drop right in your axle. That's as high as you can go with the dana 60 you have.

Used 3.54 Dana 60 gears= $25-$50
Proffessional installation= $150

$200 there

A good used 80%+ set of 235/85R16 E rated tires and 7" wide steel wheels= Around $400, maybe a lot less if you keep an eye out for a deal.

Roughly $600 investment with no real changes done to your truck, nothing hacked up or a failure prone overdrive and electronics added. A small investment like that makes sense for a truck that isn't worth more than a few grand and will actually pay for itself in mileage savings and increased engine life.[/quote]

Coz,
You should take another look at Average F-250's advice. Unless you have deep pockets for an overdrive, I would first try a slightly used set of taller tires, and if you still have good low end power and a desire to lower highway RPMs, then re-gear your Dana 60 to 3.54. If you're unhappy with the 3.54 gears and the taller tire, switch back to your original tires, and consider swapping in a 300 six and M5r2 5-speed. The 300/M5R2 combo should net you 65-70 MPH @ 2000 RPMs with 3.54 gears and your current tires, but you'll lose some of that passing lane acceleration if the six isn't built right.

[cozadlance2]

Yes. Seems averagef250 is quite right. This is my plan.
That and buying a shortbed and picking member's brains on how to make a monster out of it. 1 truck for work and 1 for after work.